Integrating treatment processes of coffee processing mill effluent for reclamation of secondary resources

As coffee is becoming a daily beverage, the coffee processing industry keeps expanding due to the perpetual demands from the global community. Alas, this great demand has also led to large production of wastewater. Coffee processing mill effluent is characterised as acidic wastewater, with high content of organic compounds, pungent odours and colours. It threatens aquatic life, human health and the environment. Thus, there is an urge to seek appropriate methods to treat the effluents so that they comply with regulated environmental limits before dismissal. Realising the importance of green technology and sustainability, the United Nations have initiated a proactive plan known as Sustainable Development Goals to be implemented by nations around the globe to ensure better future for tomorrow. This manuscript outlines a review of coffee processing and its generated wastes, conventional wastewater treatments and current practices. Based on the compiled data, this review aims to highlight the valorisation of coffee processing mill effluent treatment by introducing an environmentally friendly integrated treatment system while adopting the 'zero-waste discharge concept'. This integrated system consists of natural coagulation-flocculation, natural adsorption and phytoremediation to treat specific contam-inants in respective effluents. Highlighting the 'zero-waste discharge concept', all by-products from the proposed system can be reclaimed as secondary resources.

Automated summary

Coffee processing generates large amounts of acidic wastewater with high levels of organic compounds, pungent odors and colors, posing threats to aquatic life, human health and the environment. To address this issue, a review paper introduces an environmentally friendly integrated treatment system that utilizes natural coagulation-flocculation, natural adsorption and phytoremediation to treat specific contaminants in coffee processing mill effluent. This system aligns with the concept of 'zero-waste discharge' and enables the reclamation of all by-products as secondary resources.